A Laser System for Real-Time Measurement of the 129I and NO2 Concentrations in a Spent Nuclear Fuel Reprocessing Medium

A laser system was developed for real-time detection of the global radionuclide 129I and NO2 during spent nuclear fuel reprocessing. This system was used for determining the concentrations of these substances in a gas stream under actual conditions of nitric acid dissolution of spent nuclear fuel at the Khlopin Radium Institute, Research and Production Association. The tests showed that the laser system is suitable for measuring both the 129I and NO2 concentrations directly in the gas phase during spent nuclear fuel reprocessing (this is essential for monitoring this process and controlling the dissolution cycle safety) and in the gases emitted by radiochemical enterprises. The sensitivity with respect to 129I, achieved with the laser system developed, also makes it suitable for real-time monitoring of 129I and NO2 at the maximum permissible concentration (MAC) level. This will allow evaluation of the environmental condition of air in the working areas of radiochemical enterprises, as well as in residential areas.